If you're really good, you can toy around like that even with people who're quite proficient. I haven't seen it myself, but my sifu said that his teacher, grandmaster Al Dacascos, who's a first generation martial arts hall of famer, really is that good in his sixties, and on the wikipedia page of Kenshiro Abbe, it says that he recalled how his own kendo instructor, a 75 year old tenth dan (back when tenth dans in kendo actually still existed) couldn't be touched by any of the students or younger instructors.